alpha-(dialkylamino)-6-phenyl-o-cresol esters



United States Patent 2,872,47 7 a-(DIALKYLAMINO)-6-PHENYL-O-CRESOLESTERS Raymond H. Rigterink, Midland, Mich., assignor to The DowChemical Company, Midland, Mich, a corporation of Delaware No Drawing.Application April 5, 1957 Serial No. 650,853

6 Claims. (01160-476 In this and succeeding formulae, each R representsloweralkyl, Z represents lower alkyl, lower alkenyl or phenyl, and Xrepresents hydrogen or chlorine. The terms lower alkyl and lower alkenylas employed in the present specification and claims refer to the alkyland alkenyl radicals containing not to exceed 4 carbon atoms. The estersare oily liquids and the mineral acid addition salts of the esters arecrystalline solids which are somewhat soluble in many organic solventsand of very low solubility in water. They are active as plant growthcontrol materials and are adapted to be employed in dust and spraycompositions for the control of the growth and the kiling of weeds andfor the sterilization of soil with regard to the growth of plants. 7

The new hydrobromide and hydrochloride salts of the new esters may beprepared by condensing an organic acyl halide having the formula llChlorine Bromine with an a-(dialkylamino)-6-phenyl-o-cresol compoundhaving the formula -In carrying out the reaction, the acyl chloride orbro- 7o mide, and a-(dialkylamino)-6 phenyl-o-creso1 compound are mixedtogether one with the other, and injan inert organic solvent such astoluene or benzene. The contacting of the reactants is carried outportionwise with stirring and at a temperature of from 0 to C. Duringthe reaction, the desired product sometimes precipitates in the reactionmixture as a crystalline solid. Upon completion of the reaction, thereaction mixture may be cooled to precipitate the desired product or toprecipitate further product. The product may then be separated inconventional manner such as by filtration or decantation. If desired,the product may be purified by recrystallization from a suitable organicsolvent.

The free esters of the present invention may be prepared by neutralizingthe hydrochloride or hydrobromide salts as above prepared with causticsoda or other alkali metal hydroxide. The neutralization is carried outin an inert organic solvent and takes place readily at temperatures offrom 20 to 50 C. Upon completion of the neutralization, the neutralizedmixture may be washed with water and the solvent removed by evaporationto obtain the desired ester as a liquid.

Other mineral acid addition salts, such as the nitrate, sulfate andphosphate conveniently may be produced by reacting a free ester as aboveprepared with an equimolar amount of the corresponding mineral acid. Thereaction conveniently is carried out in an inert organic solvent andtakes place smoothly at temperatures of from 20 to 50 C. During thereaction, the desired salt product precipitates in the reaction mixtureas a crystalline solid. The precipitated product may be separated aspreviously described and purified in conventional fashion.

The following examples are illustrative of the invention but are not tobe construed as limiting:

Example 1.-5-chl0ro-3-(din'zethylaminomethyl)-2- biphenylyl acetatehydrochloride I 3 CH2N(CH3)2-HC1 Acetayle chloride (15.7 grams, 0.2mole) was added portionwise with stirring and cooling to 52.3 grams (0.2mole) of 4 chloro a (dimethylamino) 6 phenylo-cresol dissolved in 250milliliters of toluene. The addition was carried out over a period of 20minutes and at a temperature of from 20 to 30 C. Toward the end of theaddition, a crystalline solid precipitated in the reaction mixture.Following the addition, the stirring was continued for 40 minutes andthe reaction vessel and contents thereafter coo-led in an ice-waterbath. The crystalline precipitate was separated by filtration to obtaina 5 chloro-3-(dimethylarninomethyl)-2-biphenylyl acetate hydrochlorideproduct. This product was washed with cold toluene, dried and the driedproduct found to melt at 2l9-221 C.

Example 2.-5-chl0r0-3-(dimethylaminomethyl)-2- biphenylyl bcnzoatehydrochloride I Benzoyl chloride (28.1 grams; 0.2 mole) was addedportionwise with stirring and over a period of about 20 aeraar'r linesolid precipitated in the reaction mixture and the minutes to 52.3 grams(0.2 mole) of l-ChlOfO-oc-(dimethylamino)-6-phenyl-o-cresol dissolved in150 milliliters of toluene. The temperature of the reaction mix turerose to from 15 to 45 C. with the addition of the benzoyl chloride.During the addition, a White crystelmixture was diluted with 100milliliters of toluene to facilitate mixing. Following the addition,stirring was continued for 30 minutes at a temperature of from 30 to 45C. and the reaction vessel and contents thereafter cooled in anice-water bath to below room temperature. During the cooling additionalprecipitate formed in the reaction mixture. The crystalline precipitatewas then separated by filtration to obtain a-chloro-3-(dimethylamincmethyl)-2-biphenylyl benzoate hydrochlorideproduct. This product was washed with cold toluene. dried and found tomelt at 202-204 C.

Example 3.-5-chl0r0-3- (dimethylaminomethyl) -2-b5- 'ph enylyl pmpionatehydrochloride Propionyl chloride (18.5 grams; 0.2 mole) was addedportionwise with stirring and over a period of minutes to 52.3 grams(0.2 mole) of 4-chloro-e-(dimethylamino) 6-phenyl-o-cresol dissolved in150 millilters of toluene. During the addition the temperature rose tofrom C. to 52 C. Stirring was thereafter continued for minutes and thereaction vessel and contents thereafter cooled in an ice-water bath.During the cooling a precipitate crystallized in the reaction mixture.The crystalline precipitate was separated by filtration to obtain a 5-chloro-3- dimethylaminomethyl) -2-biphenylyl propionate hydrochlorideproduct. This product Was Washed with cold toluene, dried and found tomelt at 222- 224 C.

Example 4.5'-chl0r0-3-(dimethylaminomethyl)-2-biphenylyl butyratehydrochloride Butyryl chloride (21.3 grams; 0.2 mole) was addedportionwise with stirring and over a period of 15 minutes to 52.3 grams(0.2 mole) of 4-chloro-ix-(dimethylamino)- Example5.5-chl0r0-3-(dimethylaminomethyl)-2-biphenylyl crotonate hydrochlorideCrotonyl chloride (20.9 grams; 0.2 mole) was slowly s added withstirring and over a period of 10 minutes to 52.3 grams (0.2 mole) of4-chloro-oi-(dimethylamino)- -phenyl-o-cresol dissolved in 150milliliters of toluene. The temperature rose to C. during the additionand 300 milliliters of addition toluene was added to the reactionmixture to facilitate mixing. Following the addition, the reactionvessel and contents were cooled in an ice-water bath. During the coolingadditional precipitate formed in the reaction mixture. The crystallineprecipitate was then separated by filtration, washed with cold tolueneand dried to obtain a 5-chloro-3-(dimethylaminomethyl) 2 biphenylylcrotonate hydrochloride product melting at 205-207 C.

Example 6 .-3- dimethylaminomethyl -2-biphenylyl acetate hydrochlorideAcetyl chloride (15.7 grams; 0.2 mole) was added portionwise withstirring to 45.4 grams (0.2 mole) of e-(dimethylamino)-6-phenyl-o-cresoldissolved in 250 milliliters of toluene. The addition was carried outover 10 minutes and at a temperature of from 22 C. to 50 C. During theaddition, a crystalline solid precipitated in the reaction mixture.Stirring was thereafter continued for 40 minutes and the reaction vesseland contents thereafter cooled in an ice-water bath. The crystallineprecipitate was separated by filtration, washed with cold toluene anddried to obtain a 3-(dimethylaminomethyl)2-biphenylyl acetatehydrochloride product. This product was recrystallized fromchlorobenzene and found to melt at 195198 C.

Example 7.-3-(dimethylaminomethyl)-2-bipheizylyl benzoate hydrochlorideBenzoyl chloride (28.1 grams; 0.2 mole) was added portionwise withstirring to 45.4 grams (0.2 mole) of w(dimethylamino)-6-phenyl-o-cresoldispersed in 250 milliliters of toluene. The addition was carried overabout 20 minutes and at a temperature of from 20 C. to 45 C. Thereaction mixture was then processed as described in Example 6 to obtaina 3-(dimethylnminomethyl)-2-biphenylyl acetate hydrochloride product.The latter product was recrystallized from ethyl alcohol and found tomelt at 242-243 C.

Example 8.-5-chl0r0-3-(dimethylaminomezhyl) -2-biphenylyl benzoate 0.05mole sodium hydroxide dispersed in 25 milliliters of water was addedslowly portionwise to 0.05 mole of5-chlor0-3-(dimethylaminomethyl)-2-biphenylyl benzoate hydrochyloridedispersed in 250 milliliters of acetone. The addition was carried outwith stirring and cooling and over a period of 15 minutes. The acetonewas then removed by vacuum distillation, the residue dissolved inmilliliters of benzene and the benzene solution washed with water. Thebenzene was then separated by fractional distillation under reducedpressure to obtain a 5-chloro-3-(dimethylaminomethyl)-2-biphenylylbenzoate product as an oily liquid residue. This product had arefractive index n/D of 1.5925 at 25 C.

Example 9 in a similar manner 5-chloro-3-(dimethylaminoiuethyl)-Z-biphenylyl butyrate hydrochloride was neutralized with sodiumhydroxide to obtain a 5-chloro-3-(dimethylaminomethyl)-2biphenylylbutyrate product having a refractive index n/D of 1.5532 at 25 C.

Example 10 Neutralization of the product of Example 1 with sodiumhydroxide in the previously described manner gave a5-chloro-3-(dimethylaminornethyl)-2-bipbenylyl acetate product having amolecular weight of 303.5.

Example 11 Nitric acid (0.2 mole) is slowly added portionwise over aperiod of 15 minutes to 0.2 mole of5-chlo-ro-3-(dimethylaminomethyl)-2-biphenylyl benzoate dispersed in 100milliliters of benzene. The addition is carried out with stirring andcooling and at a. temperature of from 20 to 30 C. During the addition acrystalline solid precipitates in the reaction mixture. This product isseparated by filtration and washed with water to obtain a5-chloro-3-(dimethylaminomethyl)-2-biphenylyl benzoate nitrate saltproduct. 5- chloro-3-(dimctbylaminomethyl)-2-biphenylyl benzoate nitratehas a molecular weight of 428.5.

In a similar manner other compounds of the present invention may beprepared of which the following are representative.

5-chloro-3-(dibutylaminomethyl)-2-biphenylyl acetate hydrobrornide byreacting 4-chloro-a-(dibutylamino)-6- phenyl-o-cresol with acetylbromide.

3-(diethylaminomethyl)-2-biphenylyl benzoate hydrobromide by reactinga-(diethylamino)-6-phenyl-o-cresol with benzoyl bromide.

B-(dimethylaminomethyl)-2-biphenylyl benzoate by neutralizing3-(dimethylaminomethyl)-2-biphenylyl benzoate hydrochloride withpotassium hydroxide.

-chloro-3-(N-methyl-N ethylaminomethyl) 2 biphenylyl butyratehydrochloride by reacting 4-Ch1010-oc-(N-methyl-N-ethylamino)-6-pheny1-o-cresol with butyryl chloride.

5-chloro-3-(diethylaminomethyl)-2-biphenylyl acrylate hydrochloride byreacting 4-ch1oro-a-(diethylamino)-6- phenyl-o-cresol with acryloylchloride.

S-(dimethylaminomethyl)-2-biphenyly1 pentenoate hydrochloride byreacting a-(dimethylamino)-6-phenyl-ocresol with pentenoyl chloride.

. The new esters have been tested and found effective as herbicides. i.e. for the killing weeds. For such use the products may be dispersed onan inert finely divided solid and employed as dusts. Also, such mixturesmay be dispersed in water with the aid of a wetting agent, and theresulting aqueous suspensions employed as sprays. In other procedures,the products may be employed as constituents of oil-in-water emulsions,or water dispersions with or Without the addition of wetting, dispersingor emulsifying agents. In representative operations substantiallycomplete controls of the growth of the seeds and emerging seedlings ofcrabgrass were obtained when5-chloro-3-(dimethylaminomethyl)-2-biphenylyl butyrate hydrochloride wasdispersedin soil at a dosage of 5 pounds per acre.

The a-(dialkylamino)-6-phenyl-o-cresol compounds employed as startingmaterials in accordance with the present invention may be prepared byreacting together an appropriately substituted phenol, formaldehyde anda suitable dialkylamine. In a convenient method of carrying out thereaction, one molecular proportion of formaldehyde is added to a mixturecomprising one molecular proportion of each of the phenol and aminereactants in a solvent such as ethanol. The reaction takes place readeily at temperatures above 20 C. with the production of the desiredproduct and water of reaction. Upon completion of the reaction, 1creaction mixture may be cooled and filtered to separate the desiredcresol product as a crystalline solid.

I claim: 1. A compound selected from the group consisting of (A) estershaving the formula it o-o-z /R 2 CHa-N 1 a e 4 R wherein each Rrepresents lower alkyl, Z represents a member of the group lower alkyl,lower alkenyl and phenyl, and X represents a member of the grouphydrogen and chlorine, and (B) the mineral acid addition salts of saidester compounds.

2. 5-chloro-3-(dimethylaminomethyl) 2 biphenylyl acetate.

3. 5-chloro-3-(dimethylaminomethyl) 2 biphenylyl benzoate hydrochloride.

4. 5-chloro-3-(dimethylaminomethyl) 2 biphenylyl propionatehydrochloride.

5. 5-chloro-3-(dirnethylaminomethyl) 2 biphenylyl crotonatehydrochloride.

6. 3-(dimethylaminomethyl)-2-biphenylyl acetate hydrochloride.

Christiansen et a1 Dec. 27, 1938 Bruson Oct. 28, 1941 UNITED STATESPATENT OFFICE CERTIFICATE OF CORRECTION Patent NCO. 2,872,477 February:1. p 195'?) Raymond Hr, Bigterink It is hereby certified that errorappears in theprinted specification of the above numbered patentrequiring correction and that the said Letters .Patent should read ascorrected below.

Column 1, line 38, for "kiling read me killing celuinn 2, line 45, for"Aceteyle" read me Ac'etyl eolunm 3, line 1, strike out "line solidprecipitated in the reaction mixture the" end insert the same after"nrystal=" in line 6,, same column; column A, line 3C for "bydro.ehyloride" reed hydrochloride ===*a Signed and sealed this 22nd day ofSeptember 195% (SEAL) Attest:

KARL E0 wAXLiNEC ROBERT C. WATSON Attesting Officer Commissioner ofPatents

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF (A) ESTERS HAVINGTHE FORMULA